Composite material for reducing low-frequency structure-borne noise indoors and preparation method thereof

Abstract

The present invention relates to the technical field of vibration damping and noise reduction materials, and specifically to a composite material for reducing low-frequency structural noise indoors and a preparation method thereof. The composite material consists of a three-layer structure, namely a high-density damping layer, a low-density sound insulation layer and a porous sound-absorbing layer. By stacking the high-density damping layer, the porous sound-absorbing layer and the low-density sound insulation layer in sequence, bonding the layers of material together with an adhesive, forming the whole by hot pressing or cold pressing, and bonding it to the indoor wall or floor, indoor low-frequency structural noise control is achieved. The composite material for reducing low-frequency structural noise indoors of the present invention adopts a unique layered structure design, effectively absorbs and isolates low-frequency noise, and achieves efficient sound absorption effect while ensuring lightweight, thereby improving the indoor low-frequency noise environment. The preparation method is simple to operate, has low production cost, high production efficiency, and can be used for large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration-damping and noise-reducing materials, in particular to a composite material for reducing low-frequency structural noise indoors and a preparation method thereof. Background Art

[0002] With the acceleration of urbanization and the improvement of living standards, people's demands for quality of life are also increasing. Indoor noise pollution has become a focus of attention. Low-frequency noise, in particular, affects people's physical and mental health. Rail transit and road traffic are the two main sources of low-frequency structure-borne noise.

[0003] As a fast and environmentally friendly mode of transportation, rail transit is experiencing increasing frequency and capacity. However, the vibrations generated by trains are transmitted through the tracks to the ground and surrounding buildings, generating low-frequency structure-borne noise. This noise is particularly noticeable in tunnels, along viaducts, and near residential areas. Urban road traffic is another significant contributor to low-frequency structure-borne noise. Low-frequency vibrations generated by vehicles, especially heavy vehicles, can be transmitted through the ground into building structures, causing low-frequency noise indoors. This low-frequency noise not only disrupts people's normal rest and work, but long-term exposure can also lead to negative psychological and physiological effects. Its strong penetrating power makes it difficult to effectively control with traditional sound insulation materials, posing a direct threat to the quality of life of residents along the lines. Summary of the Invention

[0004] To overcome the shortcomings and deficiencies of existing technologies, the present invention provides a composite material for reducing low-frequency structure-borne noise indoors. This composite material utilizes a unique layered structure to effectively absorb and block low-frequency noise, achieving high sound absorption while maintaining lightweight performance, thereby improving the low-frequency noise environment indoors.

[0005] Another object of the present invention is to provide a method for preparing a composite material for reducing low-frequency structure-borne noise indoors. The preparation method is simple to operate, convenient to control, has low production cost, and high production efficiency. The prepared composite material effectively reduces low-frequency noise indoors, can be used for large-scale production, and has good application effects and promotion value.

[0006] The purpose of the present invention is achieved through the following technical solution: a composite material for reducing low-frequency structure-borne noise indoors, the composite material consisting of a three-layer structure, namely a high-density damping layer and a low-density sound insulation layer on the outside, and a porous sound-absorbing layer in the middle.

[0007] Preferably, the high-density damping layer comprises the following raw materials in parts by weight:

[0008] Matrix material A 12-15 parts

[0009] Filling material A 8-10 parts

[0010] Damping agent A 1-2 parts

[0011] Additive A 0.2-0.5 parts

[0012] Preferably, the matrix material A is polyethylene, which is the main body of the high-density damping layer.

[0013] Preferably, the filling material A is metal powder with a particle size controlled at 20-50 μm, and is mainly used to increase the density and rigidity of the composite material.

[0014] Preferably, the damping agent A is nitrile rubber, which is mainly used to effectively absorb vibration energy.

[0015] Preferably, the auxiliary agent A is an anti-aging agent, which can improve the durability and stability of the material.

[0016] By using a high-density damping layer, this invention significantly improves the vibration absorption and sound insulation performance of composite materials. Its high density and high rigidity effectively absorb and dissipate vibration energy, reducing the propagation of low-frequency noise while also enhancing the material's durability and stability, making it suitable for long-term use.

[0017] Preferably, the low-density sound insulation layer comprises the following raw materials in parts by weight:

[0018] Matrix material B 10-12 parts

[0019] Filling material B 5-7 parts

[0020] 2-3 parts of soundproofing agent B

[0021] Additive B 0.1-0.3 parts

[0022] Preferably, the matrix material B is polyurethane foam, which is mainly used to provide basic structural support and sound insulation effects.

[0023] Preferably, the filling material B is glass beads or expanded perlite, and the particle size is controlled at 50-100 μm, which is used to reduce the density of the material, enhance the sound insulation performance, and keep the material lightweight.

[0024] Preferably, the sound insulation agent B is calcium silicate or aluminum silicate, which is used to improve the sound insulation performance of the material, especially the insulation effect on low-frequency noise.

[0025] Preferably, the auxiliary agent B is a fire retardant or a mildewproofing agent, which is used to improve the fire resistance, mildew resistance and long-term stability of the material.

[0026] The present invention adopts a low-density sound insulation layer to provide a physical barrier to block or reduce the transmission of sound waves. It can provide excellent sound insulation effect while maintaining lightweight and effectively reduce the spread of low-frequency noise.

[0027] Preferably, the porous sound-absorbing layer comprises the following raw materials in parts by weight:

[0028] Matrix material C 15-20 parts

[0029] Sound-absorbing filler C 10-15 parts

[0030] Binder C 3-5 parts

[0031] Additive C 0.5-1 part

[0032] Preferably, the matrix material C is polyurethane foam or polyester fiber, and the porosity is controlled at 60%-80%. It serves as the main material of the porous sound-absorbing layer and provides basic structural support and sound-absorbing performance.

[0033] Preferably, the sound-absorbing filler C is glass fiber or foam particles, and the particle size is controlled at 100-200 μm, which can increase the sound absorption performance of the material, especially the absorption effect of low-frequency noise.

[0034] Preferably, the adhesive C is polyvinyl alcohol or acrylate, which is used to bond the matrix material and the sound-absorbing filler together to enhance the integrity and structural stability of the material.

[0035] Preferably, the auxiliary agent is a fire retardant or a mildewproofing agent, which can improve the fire resistance, mildew resistance and long-term stability of the material.

[0036] The present invention adopts a porous sound-absorbing layer and utilizes the porous structure of the material to absorb sound waves, thereby providing excellent sound absorption effect, especially absorption of low-frequency noise, significantly reducing indoor low-frequency structure-borne noise and improving indoor environmental quality.

[0037] The present invention prepares a composite material for reducing low-frequency structure-borne noise indoors by adopting the above-mentioned high-density damping layer, low-density sound insulation layer and porous sound-absorbing layer, and strictly controls the amount of each raw material. It can significantly reduce low-frequency noise, improve sound absorption performance, enhance material stability, and also has multiple functions such as fire prevention, mildew resistance, and moisture resistance. It is suitable for various indoor environments and improves the comfort of living and working environments.

[0038] Another object of the present invention is achieved by the following technical solution: A method for preparing the composite material for reducing low-frequency structure-borne noise indoors as described above comprises the following steps:

[0039] (1) Weigh the matrix material A by weight, add the filler material A with a particle size of 20-50 μm by weight to the matrix material A, and mix them evenly; add the damping agent A by weight and continue stirring until uniform; add the auxiliary agent A by weight and ensure that it is fully mixed to form a mixture; pour the mixture into a mold, and form it by hot pressing or cold pressing to obtain a high-density damping layer;

[0040] (2) Weigh the matrix material B by weight, add the filler material B with a particle size of 50-100 μm by weight to the matrix material B, and mix them evenly; add the sound insulation agent B by weight and continue stirring until uniform; add the auxiliary agent B by weight and ensure that it is fully mixed to form a mixture; pour the mixture into a mold and form it by hot pressing or cold pressing to obtain a low-density sound insulation layer;

[0041] (3) Weigh the matrix material C in parts by weight, add the sound-absorbing filler C with a particle size of 100-200 μm in parts by weight to the matrix material C, and mix them evenly; add the binder C in parts by weight and continue stirring until they are evenly mixed; add the auxiliary agent C in parts by weight and ensure that they are fully mixed to form a mixture; pour the mixture into a mold and form it by hot pressing or cold pressing to obtain a porous sound-absorbing layer;

[0042] (4) Stack the high-density damping layer, porous sound-absorbing layer and low-density sound-insulating layer in sequence, and use adhesive to bond the layers together to ensure strong bonding and no delamination; place the combined materials into a mold and form the whole by hot pressing or cold pressing to ensure the integrity and dimensional stability of the composite material;

[0043] (5) The formed composite material is subjected to surface treatment and coated with a waterproof layer to form the final composite material;

[0044] (6) The composite material obtained in step (5) is bonded to the indoor wall or floor to achieve indoor low-frequency structure-borne noise control.

[0045] The beneficial effects of the present invention are as follows: (1) through the multi-layer structural design of high-density damping layer, low-density sound insulation layer and porous sound absorbing layer, low-frequency noise is effectively absorbed and isolated, the indoor low-frequency noise level is significantly reduced, and the indoor sound environment is improved; (2) the high-density damping layer effectively absorbs vibration energy, the low-density sound insulation layer isolates the noise propagation, and the porous sound absorbing layer further absorbs the residual noise, and the three work together to achieve a high-efficiency sound absorption effect; (3) through the reasonable selection and proportioning of matrix materials, filling materials, adhesives and additives, the composite material has good mechanical strength, durability and stability, and is suitable for long-term use; (4) although the composite material has a high-density damping layer, the overall material remains lightweight through the design of low-density sound insulation layer and porous sound absorbing layer, which is convenient for construction and installation; (5) the composite material has multiple functions such as fire resistance, mildew resistance, moisture resistance, etc., and is suitable for various indoor environments; (6) the preparation method is simple to operate, easy to control, low in production cost, high in production efficiency, and suitable for large-scale production. At the same time, environmentally friendly materials are selected to reduce pollution to the environment, meeting the requirements of sustainable development. DETAILED DESCRIPTION

[0046] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the embodiments. The contents mentioned in the embodiments are not intended to limit the present invention.

[0047] Example 1

[0048] A composite material for reducing low-frequency structure-borne noise indoors. The composite material consists of a three-layer structure, comprising a high-density damping layer and a low-density sound insulation layer on the outside, and a porous sound-absorbing layer in the middle.

[0049] The high-density damping layer comprises the following raw materials in parts by weight:

[0050] 15 parts of matrix material A

[0051] Filling material A 10 parts

[0052] Damping agent A 2 parts

[0053] 0.5 parts of additive A

[0054] The matrix material A is polyethylene.

[0055] The filling material A is iron powder with a particle size of 25-30 μm.

[0056] The damping agent A is nitrile rubber.

[0057] The auxiliary agent A is an anti-aging agent.

[0058] The low-density sound insulation layer comprises the following raw materials in parts by weight:

[0059] 12 parts of matrix material B

[0060] Filling material B 7 parts

[0061] 3 parts of soundproofing agent B

[0062] 0.3 parts of additive B

[0063] The matrix material B is polyurethane foam.

[0064] The filling material B is glass microbeads, and the particle size is controlled at 60-70 μm.

[0065] The sound insulation agent B is calcium silicate.

[0066] The auxiliary agent B is a fire retardant.

[0067] The porous sound-absorbing layer comprises the following raw materials in parts by weight:

[0068] 20 parts of matrix material C

[0069] 15 parts of sound-absorbing filler C

[0070] 5 parts of adhesive C

[0071] 1 part of additive C

[0072] The matrix material C is polyester fiber, and the porosity is controlled at 75%.

[0073] The sound-absorbing filler C is glass fiber, and the particle size is controlled at 100-120 μm.

[0074] The binder C is polyvinyl alcohol.

[0075] The auxiliary agent is a fire retardant.

[0076] A method for preparing the composite material for reducing low-frequency structure-borne noise indoors as described above comprises the following steps:

[0077] (1) Weigh the matrix material A by weight, add the filler material A with a particle size of 25-30 μm by weight to the matrix material A, and mix them evenly; add the damping agent A by weight and continue stirring until uniform; add the auxiliary agent A by weight and ensure that it is fully mixed to form a mixture; pour the mixture into a mold, and form it by hot pressing or cold pressing to obtain a high-density damping layer;

[0078] (2) Weigh the matrix material B by weight, add the filler material B with a particle size of 60-70 μm by weight to the matrix material B, and mix them evenly; add the sound insulation agent B by weight and continue stirring until uniform; add the auxiliary agent B by weight and ensure that it is fully mixed to form a mixture; pour the mixture into a mold and form it by hot pressing or cold pressing to obtain a low-density sound insulation layer;

[0079] (3) Weigh the matrix material C in parts by weight, add the sound-absorbing filler C with a particle size of 100-120 μm in parts by weight to the matrix material B, and mix them evenly; add the binder C in parts by weight and continue stirring until they are evenly mixed; add the auxiliary agent C in parts by weight and ensure that they are fully mixed to form a mixture; pour the mixture into a mold and form it by hot pressing or cold pressing to obtain a porous sound-absorbing layer;

[0080] (4) Stack the high-density damping layer, porous sound-absorbing layer and low-density sound-insulating layer in sequence, and use adhesive to bond the layers together to ensure strong bonding and no delamination; place the combined materials into a mold and form the whole by hot pressing or cold pressing to ensure the integrity and dimensional stability of the composite material;

[0081] (5) The formed composite material is subjected to surface treatment and coated with a waterproof layer to form the final composite material;

[0082] (6) The composite material obtained in step (5) is bonded to the indoor wall or floor to achieve indoor low-frequency structure-borne noise control.

[0083] Comparative Example 1

[0084] The invention discloses a composite material for reducing low-frequency structure-borne noise indoors. The composite material consists of two layers, namely a high-density damping layer and a low-density sound insulation layer.

[0085] The high-density damping layer comprises the following raw materials in parts by weight:

[0086] 13 parts of matrix material A

[0087] Filling material A 8 parts

[0088] Damping agent A 1.5 parts

[0089] 0.4 parts of additive A

[0090] The matrix material A is polyethylene.

[0091] The filling material A is copper powder, and the particle size is controlled at 30-40 μm.

[0092] The damping agent A is nitrile rubber.

[0093] The auxiliary agent A is an anti-aging agent.

[0094] The low-density sound insulation layer comprises the following raw materials in parts by weight:

[0095] 12 parts of matrix material B

[0096] Filling material B 8 parts

[0097] 3 parts of soundproofing agent B

[0098] 0.3 parts of additive B

[0099] The matrix material B is polyester fiber.

[0100] The filling material B is expanded perlite, and the particle size is controlled at 60-70 μm.

[0101] The sound insulation agent B is aluminum silicate.

[0102] The auxiliary agent B is a mildew inhibitor.

[0103] A method for preparing the composite material for reducing low-frequency structure-borne noise indoors as described above comprises the following steps:

[0104] (1) Weigh the matrix material A by weight, add the filler material A with a particle size of 30-40 μm by weight to the matrix material A, and mix them evenly; add the damping agent A by weight and continue stirring until uniform; add the auxiliary agent A by weight and ensure that it is fully mixed to form a mixture; pour the mixture into a mold and form it by hot pressing or cold pressing to obtain a high-density damping layer;

[0105] (2) Weigh the matrix material B by weight, add the filler material B with a particle size of 60-70 μm by weight to the matrix material B, and mix them evenly; add the sound insulation agent B by weight and continue stirring until uniform; add the auxiliary agent B by weight and ensure that it is fully mixed to form a mixture; pour the mixture into a mold and form it by hot pressing or cold pressing to obtain a low-density sound insulation layer;

[0106] (3) Superimpose the high-density damping layer and the low-density sound insulation layer, and use adhesive to bond the layers together to ensure that the bonding is firm and there is no delamination; place the combined materials into a mold and form the whole by hot pressing or cold pressing to ensure the integrity and dimensional stability of the composite material;

[0107] (4) The formed composite material is subjected to surface treatment and coated with a waterproof layer to form the final composite material;

[0108] (5) The composite material obtained in step (4) is bonded to an indoor wall or floor, thereby completing the preparation.

[0109] Comparative Example 2

[0110] A composite material for reducing low-frequency structure-borne noise indoors. The composite material consists of a two-layer structure, namely a high-density damping layer and a porous sound-absorbing layer.

[0111] The high-density damping layer comprises the following raw materials in parts by weight:

[0112] 13 parts of matrix material A

[0113] Filling material A 12 parts

[0114] Damping agent A 1 part

[0115] 0.4 parts of additive A

[0116] The matrix material A is polyethylene.

[0117] The filling material A is iron powder with a particle size of 35-40 μm.

[0118] The damping agent A is nitrile rubber.

[0119] The auxiliary agent A is an anti-aging agent.

[0120] The porous sound-absorbing layer comprises the following raw materials in parts by weight:

[0121] 18 parts of matrix material C

[0122] 13 parts of sound-absorbing filler C

[0123] 4 parts of adhesive C

[0124] 1.5 parts of additive C

[0125] The matrix material C is polyester fiber, and the porosity is controlled at 60%.

[0126] The sound-absorbing filler C is glass fiber, and the particle size is controlled at 150-160 μm.

[0127] The binder C is polyvinyl alcohol.

[0128] The auxiliary agent is a fire retardant.

[0129] A method for preparing the composite material for reducing low-frequency structure-borne noise indoors as described above comprises the following steps:

[0130] (1) Weigh the matrix material A by weight, add the filler material A with a particle size of 35-40 μm by weight to the matrix material A, and mix them evenly; add the damping agent A by weight and continue stirring until uniform; add the auxiliary agent A by weight and ensure that it is fully mixed to form a mixture; pour the mixture into a mold, and form it by hot pressing or cold pressing to obtain a high-density damping layer;

[0131] (2) Weigh the matrix material C in parts by weight, add the sound-absorbing filler C with a particle size of 150-160 μm in parts by weight to the matrix material B, and mix them evenly; add the binder C in parts by weight and continue stirring until they are evenly mixed; add the auxiliary agent C in parts by weight and ensure that they are fully mixed to form a mixture; pour the mixture into a mold and form it by hot pressing or cold pressing to obtain a porous sound-absorbing layer;

[0132] (3) Superimpose the high-density damping layer and the porous sound-absorbing layer, and use adhesive to bond the layers together to ensure that the bonding is firm and there is no delamination; place the combined materials into a mold and form the whole by hot pressing or cold pressing to ensure the integrity and dimensional stability of the composite material;

[0133] (4) The formed composite material is subjected to surface treatment and coated with a waterproof layer to form the final composite material;

[0134] (5) The composite material obtained in step (4) is bonded to an indoor wall or floor to complete the preparation.

[0135] Through calculation, the noise reduction performance results of the composite materials for reducing low-frequency structure-borne noise indoors in Examples 1-2 and Comparative Examples 1-2 at 16-250 Hz are shown in Table 1 below.

[0136] Table 1 Noise reduction performance results of composite materials used in Example 1 and Comparative Examples 1-2 for reducing low-frequency structure-borne noise indoors

[0137] Test items Example 1 Comparative Example 1 Comparative Example 2 16-250Hz noise reduction performance (dB) 20.5 3.1 2.6

[0138] According to the analysis of the calculated data in Table 1, the composite material for reducing indoor low-frequency structure noise according to the present invention has good noise reduction performance in the range of 16-250Hz, and can effectively reduce indoor low-frequency noise. Compared with the composite material without any noise reduction measures, the indoor low-frequency noise of the composite material of Example 1 is significantly reduced; while the samples of Comparative Example 1 and Comparative Example 2, which lack the core noise reduction structural layer, have certain low-frequency noise reduction efficacy, but do not show obvious noise reduction effect. This also confirms that the composite material of the present invention achieves the noise reduction effect of indoor low-frequency structure noise through the synergistic effect between various structures, and has obvious innovation.

[0139] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the scope of protection of the present invention.

Claims

1. A composite material for reducing low-frequency structure-borne noise indoors, characterized by: The composite material consists of a three-layer structure, namely a high-density damping layer and a low-density sound insulation layer on the outside, and a porous sound-absorbing layer in the middle; The high-density damping layer comprises the following raw materials in parts by weight: 12-15 parts of matrix material A, 8-10 parts of filler material A, 1-2 parts of damping agent A, and 0.2-0.5 parts of additive A; the matrix material A is polyethylene; the filler material A is metal powder with a particle size controlled at 20-50 μm; the damping agent A is nitrile rubber; and the additive A is an anti-aging agent. The low-density sound insulation layer comprises the following raw materials in parts by weight: 10-12 parts of matrix material B, 5-7 parts of filling material B, 2-3 parts of sound insulation agent B, and 0.1-0.3 parts of auxiliary agent B; the matrix material B is polyurethane foam; the filling material B is glass beads or expanded perlite, with a particle size controlled at 50-100 μm; the sound insulation agent B is calcium silicate or aluminum silicate; and the auxiliary agent B is a fire retardant or mildew inhibitor. The porous sound-absorbing layer comprises the following raw materials in parts by weight: 15-20 parts of matrix material C, 10-15 parts of sound-absorbing filler C, 3-5 parts of binder C, and 0.5-1 part of additive C; the matrix material C is polyurethane foam or polyester fiber, with a porosity controlled at 60%-80%; the sound-absorbing filler C is glass fiber or foam particles, with a particle size controlled at 100-200 μm; the binder C is polyvinyl alcohol or acrylate; and the additive is a fire retardant or mildew inhibitor.

2. A method for preparing a composite material for reducing indoor low-frequency structure-borne noise according to claim 1, characterized in that: The following steps are involved: (1) Weigh the matrix material A by weight, add the filler material A with a particle size of 20-50 μm by weight to the matrix material A, and mix them evenly; add the damping agent A by weight and continue stirring until uniform; add the auxiliary agent A by weight and ensure that it is fully mixed to form a mixture; pour the mixture into a mold, and form it by hot pressing or cold pressing to obtain a high-density damping layer; (2) Weigh the matrix material B by weight, add the filler material B with a particle size of 50-100 μm by weight to the matrix material B, and mix them evenly; add the sound insulation agent B by weight and continue stirring until uniform; add the auxiliary agent B by weight and ensure that it is fully mixed to form a mixture; pour the mixture into a mold and form it by hot pressing or cold pressing to obtain a low-density sound insulation layer; (3) Weigh the matrix material C in parts by weight, add the sound-absorbing filler C with a particle size of 100-200 μm in parts by weight to the matrix material C, and mix them evenly; add the binder C in parts by weight and continue stirring until they are evenly mixed; add the auxiliary agent C in parts by weight and ensure that they are fully mixed to form a mixture; pour the mixture into a mold and form it by hot pressing or cold pressing to obtain a porous sound-absorbing layer; (4) Stack the high-density damping layer, porous sound-absorbing layer and low-density sound-insulating layer in sequence, and use adhesive to bond the layers together to ensure strong bonding and no delamination; place the combined materials into a mold and form the whole by hot pressing or cold pressing to ensure the integrity and dimensional stability of the composite material; (5) The formed composite material is subjected to surface treatment and coated with a waterproof layer to form the final composite material; (6) The composite material obtained in step (5) is bonded to the indoor wall or floor to achieve indoor low-frequency structure-borne noise control.